For whole chickens you can't go wrong with a beer butt (or Coke, Dr Pepper, etc) setup and cooking for 4 hours or longer depending on the size. You can also inject with a marinade and cook spine down, just be careful to not put too much salt or alcohol in the marinade or you'll end up with salty dry chicken.

Whole turkeys you can cook much like a chicken, just over a longer period due to the size. Fruit stuffed into the chest cavity is a good way to add flavor and moisture during the long cooking process; just be sure to remove and dispose of the stuffing prior to serving as it typically doesn't taste so great after half a day of cooking.

For both some prep tips

Pull the pop up done timer out as they are worthless for ultra slow cooking.

Leave the skin on and fat under the skin, it helps contain the bird's natural juices and adds flavor during the cooking process.

Be sure to get the bag of giblets, liver, etc out of the chest cavity before cooking.

As you approach the end of the cooking period keep a closer eye on done-ness; it's a fine line between done and flavorful/juicy, and done and dry.

Hickory or oak are good base woods and what most of our cooking is done with. Hickory will burn hotter than oak, but for a shorter period of time so a mix of the two will give a good mix of heat and length of burn.

Avoid all evergreens and softwoods. The flavor imparted on the meat is not what most people find desirable.

Standard procedure is to load the firebox up 6 or so 18" long logs and then light the propane starter. Once the wood is burning on it's own, turn off the propane and let the initial loading of wood burn down to coals. Add another 2 or 3 logs and close down the damper baffles so you get a nice smoldering smoke rather than a clean burn. At this point if you don't have too much heat (try to be within 50F of your target temp) built up you can go ahead and put the meat on. Then add wood as needed to maintain temp; frequency will vary on the type wood, how dry (seasoned) it is and how hot you're cooking.

7) If it fits in your cooker it can be smoked or bbq'd. Don't limit yourself to just meats; vegetables and breads also smoke well.

8) 175-225F for life, with the exception of sausages and chicken wings/thighs. For those I prefer to go 250-275F. Avoid frequently opening the cooker up, you lose heat each time. If your cooker doesn't have a quality thermometer built into it, drill and install one yourself.

9) Patience, patience, patience. Don't start with an empty stomach or you'll be tempted to cook faster and hotter, and won't get the depth of flavor desired.

Just a bit of commentary based on 21 years of catering smoked/bbq'd meats.

1) If you're patient enough you'll get better results if you stay in the 175-225F range, the smoke flavor will penetrate deeper into the meat. Also, if not serving immediately let the meat cool down slowly in a cooler; the meat will be moister as a result. Other than sausages, just like grilling steaks, everything is better if you let it set 5-10 min to rest after being pulled off the heat before slicing. I also recommend rinsing off quickly with hot water as any soot that settles on the meat will cause bitterness.

2) A vertically aligned cooker can get you good results, but you have got to keep a close eye on them; the temps can spike rapidly if the water pan runs dry ruining everything. You can add some extra flavor to the meat by mixing fruit juices or wines with the water. Most also are made from thin sheet metal and even moderately light breezes can cause temp fluctuations. My preference is an older generation Oklahoma Joe's with an offset firebox prior to Brinkman buying them up. The quarter inch boiler plate steel will hold the heat in for more consistent cooking and lasts forever.

3) Tools of the trade are a real personal preference. A pair of decent leather gloves (or welding gloves if especially temp sensitive) for working around the fire can come in handy. A good meat thermometer is a must, I prefer simple guage style ones. Accurate and cheap. Heavy duty foil Spray bottle (for misting leaner cuts of meat with apple juice for moisture) Multiple sets of long handled heavy duty tongs. When lifting a 30LB turkey over your head is not the time to question having gone with bargin bin tongs. Rib rack, useful if you want to cook a lot of ribs in minimal space. It also lets you get away with not having to flip them to achieve even cooking.

4) Just say no to charcoal. For your primary heat source go with oak, hickory, pecan or a mix. Apple and peach will give meats a sweeter taste, cherry doesn't do much for flavor but gives meats a beautiful red tint. Can't really go wrong with fruit woods in general for altering the flavor of your base wood. Mesquite is a strong flavoring, start off using a little and work your way up.

5) See above

6) I'm absolutely a purist and almost always prefer no rub. Biggest thing I can say here is experiment and see what you like.